Solenoid valve having the solenoid encapsulated within a dielectric cover



1966 J. A, KOZEL ETAL 3,289,697

SOLENOID VALVE HAVING THE SOLENOID ENCAPSULATED WITHIN A DIELECTRICCOVER Filed Jan. 9, 1964 INVENTORS JAIME! 4L K0254 United States PatentOffice 3,289,697 Patented Dec. 6, 1966 3,289,697 SOLENOID VALVE HAVINGTHE SOLENOID EN- CAPSULATED WITHIN A DIELECTRIC COVER James A. Kozel,Franklin, Emil Robert Plasko, Walled Lake, and Henry W. Kogan, Oak Park,Mich., assignors to American Radiator & Standard Sanitary Corporation,New York, N.Y., a corporation of Delaware Filed Jan. 9, 1964, Ser. No.336,685 3 Claims. (Cl. 137-606) This invention relates to solenoidvalves, as for example solenoid-operated mixing valves used in supplyingwater of selected temperatures to domestic clothes washing machines. I a

One object of the invention is to provide a solenoid valve in which theelectrical coil is encapsulated within a molded dielectric cover.

Another object is to provide a solenoid valve having novel means fordiffusing the magnetic flux, where-by to achieve a relatively low costcoil.

An additional object of the invention is to provide a pilot-operatedvalve wherein the pilot element operates against a fixed pilot port,whereby the pilot element can have a fairly short travel withoutinterferring with movement of the main valve element.

A further object is to provide a solenoid-operated mixing valve whereintwo solenoid coils are energized by only three terminals, whereby topermit economies in the lead-in wiring.

A general object is to provide a pilot-operated mixing valve which canbe manufactured as a relatively compact low cost device.

In the drawings:

FIGURE 1 is a top plan view of one embodiment of the invention;

FIG. 2 is an enlarged sectional view taken taken substantially on line2-2 in FIG. 1;

FIG. 3 is a sectional view taken substantially on line 33 in FIG. 2; and

FIG. 4 is a sectional view taken substantially on line 4-.4 in FIG. 2.

In the drawings numeral refers to a pilot-operated mixing valve having avalve body 12 and a molded dielectric cover element 14 secured thereonby three screws 16. Body 12 is contoured to provide a tubular inlet 18for fluid of one temperature, a tubular inlet 20 for fluid of anothertemperature, and a tubular outlet 22. As shown in FIG. 2, inlet 18supplies fluid to an annular inlet chamber 24 which is concentric withan outlet chamber 26. Flow of fluid from chamber 24 into chamber 26 iscontrolled by a rubber diaphragm 28. Chamber 26 then directs the fluidinto a horizontal discharge duct 30 which extends within tubular outlet22.

Diaphragm 28 is positioned within a recess in cover 14, whereby tocooperate therewith in defining a pressure chamber 25. Additionalrecesses in the cover provide an exhaust chamber 27 and a connectorchannel 23. As shown in FIG. 2, chamber 27 accommodates an enlargeddisc-type valve element 31 which cooperates with a guided plunger 35 toform an armature designated generally by numeral 33. When electric coil32 is energized armature 33 is drawn upwardly to open a pilot port 34formed in the fixed rubber element 36. Port 34 overlies the end portionof a pilot channel 37 which connects with duct 30.

When port 34 is open, fluid can flow from inlet chamber 24 through bleedport 29, channel 23, chamber 27, port 34, channel 37, and duct 30. Thepressure differential between the fliud in chambers 24 and 25 is thusenabled to bias diaphragm 28 upwardly to permit the main body of fluidto flow from chamber 24 through i which controls the fluid flowing frominlet 20 to outlet 22.

Inlet 18 may be connected with the source of hot fluid, and inlet 20 maybe connected with the source of cold fluid, or vice versa. The electriccoils may be energized singly or collectively to provide the desiredflows. Pref- 1 erably the duplicate rubber parts 36, 28, 36a and 28a areformed as an integral one piece element. To provide an adequate sealbetween the various chambers the integral rubber element may be providedwith upstanding periph eral ribs 19, 21, 19a and 21a fitting withinmating grooves in cover 14.

As shown in FIG. 2, illustrated electric coil 32 is wound on a spool 46which has an upper end flange 39 and a lower end flange 38. The lowerend flange is provided with two slots which grippingly receive thepronglike end portions of spade-type terminals 40 and 42. The terminalsmay be connected with the ends of the coil wires in any suitable manner.However for illustration purposes we have shown the inner end wire ofcoil 32 extending through a slot 44 in spool flange 38% and thencewrapped about terminal 40, as at 48. The outermost wire of the coil maybe drawn under the lower surface of flange 38 and thence wrapped aboutterminal 42, as at 52. Solder may be applied to the wrapped portions 48and 52 to provide good electrical connections. Similar wrapping andsoldering operations may be utilized for the wire of coil 32a.

Preferably, although not necessarily, only three of the tour illustratedterminals are directly accessible to the lead-in wiring. Terminal 42 istherefore shortened and is connected with terminal 421: by a bridging;portion 43. The one piece element formed by portions 42, 43 and 42a thusconstitutes a single common terminal which is connected with an end wireof each coil. In the illustrated arrangement this common terminalconnects with.the wire ends which extend from the outermost windings ofthe coils, although the common terminal could be connected with thewires which extend from the innermost windings of the coils. If desired,the wire portions 52 and 52a could be wrapped about a common area of theterminal; in this case terminal 42 and bridge 43 could be eliminated.

The use of three terminals for the two coils is not particularlyadvantageous in reducing the cost of the solenoid valve, but it isadvantageous in permitting some cost reduction for the lead-in wiring.The two coils can be electrically energized from a single three-wirecable which is less costly than two separate two-wire cables necessaryunder prior art practice. Preferably the lead-in wiring is connectedwith terminals 40, 42a and 40a by means of a female plug having :anelectrical clamp portion adapted to register with each of the projectingterminal portions. As shown in FIG. 3, the terminals are non-symmetricalso that the female plug must be inserted onto the terminals in thecorrect electrical position.

Each electrical coil 32 or 32:: is encapsulated within the moldeddielectric material for cover 14. Preferred material for both the coverand spool is epoxy. During the handling and molding operations it may beadvantageous to have the two spools 46 and 46a connected together as aunitary assembly. For this purpose one or both of the spool flanges 38and 39, and 38a and 39a, may have cooperating snap-on connector portionsformed thereon. As shown in FIG. 3, the snap-on portions comprisesemi-resilient male fingers 54 on spool flange 38 and a companion slotor recess 56 in spool flange 38.

As shown in FIG. 2, the spool 46 for coil 32 has inserted therein a polepiece or magnetic core which comprises a post portion 58 and an enlargedhead portion 60. Similarly, armature 33 comprises a movable post orplunger portion 35 and an enlarged head portion 31. The employment ofarmature and core elements having enlarged head portions has been foundto considerably improve the performance of the solenoid, particularly asregards reduction in the amount of copper going into the coil. It isbelieved that the enlarged head portions have the function of diffusingthe flux, whereby to prevent flux concentrations at the ends of thecoil. The flux apparently is radiated from the enlarged head portionswith comparatively small reluctance (i.e., compared to an arrangementnot having the enlarged head portions). There is of course a relativelylong axial gap between the circumferential edge areas of the twoenlarged head portions 60 and 31. However the relatively large surfaceareas of these portions provides a large total effective cross sectionalarea for the return flux so that the effective reluctance of themagnetic circuit is satisfactorily small. The coil design is thereforesuited to the use of relatively small amounts of copper wire in thewindmg.

A further factor contributing to reduction in copper is the fact thatpilot valve portion 31 operates against a fixed port located remote fromelement 28. Main valve element 28 can have an extensive travel inaccordance with the main flow requirements, and pilot element 31 canhave a lesser travel sufiicient to bleed chambers 25 and 27 throughorifice 34. The small pilot element travel can be provided by arelatively small coil having a small mass of copper.

The primary features of this invention are believed to reside in theconcept of encapsulating the coil or coils in a dielectric cover, theemployment of three accessible terminals to service two coils, the useof a pilot element operating against a fixed orifice, and the use ofcore and armature members having enlarged magnetic head portions locatedat opposite ends of the coil. Some variation in detail from that shownin the drawings is believed possible while still following the teachingsof the invention.

What is claimed is:

1. In a mixing valve having a pair of individually energizable solenoidcoils arranged in side-by-side relation for controlling the flow offluids through the valve: the improvement comprising a spool for eachcoil; a first terminal mounted one one spool in electrical connectionwith one end of the coil carried thereon; a second terminal mounted onthe other spool in electrical connection with one end of the coilcarried thereon; a third terminal mounted jointly on both spools iselectrical connection with the other end of each coil; and a singlecontinuous molded dielectric cover material encapsulating both coils andtheir spools; said terminals being located closely adjacent one anotherfor connection with the wires of a three wire power supply cable.

2. A mixing valve comprising a valve body having a face configured toform a pair of fixed main ports and fixed pilot ports adjacent thereto;a pair of spools arranged in side-by-side relation and individuallyregistering with each pilot port; an electrical coil wound on eachspool; a magnetic core for each coil including a post portion disposedwithin one end of the spool and an enlarged head portion overlying saidone spool end; a movable armature for each coil including a plungerdisposed within the respective spool, and an enlarged head portiondisposed between the spool and the registering pilot port; a continuousmolded dielectric cover seated on the aforementioned valve body face andencapsulating both coils; and three terminals extending within andWithout the encapsulating material; one of said terminals being mountedon one spool in electrical connection with one end of the coil carriedthereon; another of said terminals being mounted on the other spool inelectrical connection with one end of the coil carried thereon; and theremaining terminal being mounted jointly on both spools in electricalconnection with the other end of each coil.

3. A valve' comprising a valve body having a face thereof configured toform concentric inlet and outlet chambers separated by an annular mainvalve seat; said valve body having an outlet chamber in fluidcommunication with said valve seat to receive liquid therefrom; a onepiece combination gasket-diaphragm valve element of elastomeric materialdisposed on said one face of the valve body; said elastomeric elementhaving its diaphragm portion overlying the main annular valve seat tomove toward and away therefrom; a molded dielectric cover having a facethereof overlying said element; means retaining said cover, elastomericelement, and valve body together in liquid-tight relation; said coverhaving a recess in the aforementioned face; said recess being configuredto define a cavity accommodating movement of the diaphragm portion awayfrom the main valve seat, and a pilot valve element chambercommunicating with said cavity to receive liquid therefrom; a solenoidencapsulated within the cover, said solenoid comprising a dielectricspool having a hollow tubular portion defining an interior extension ofthe valve element chamber, an electrical winding wound about saidtubular portion and sealed within the cover; a pole piece for thesolenoid comprising an enlarged magnetic head portion overlying the endof the spool remote from the valve element chamber, and a post portionextending into the hollow space defined by the tubular portion; saidelastomeric element-having a pilot port extending therethrough in directalignment with the interior extension of the valve element chamber; apilot valve element comprising a magnetic armature plunger having aportion thereof slidably disposed within the chamber extension in directguided engagement with the spool interior surface; passage means forconveying pilot liquid from the inlet chamber to the aforementionedcavity; and second passage means for conveying pilot liquid from thepilot port to the outlet chamber.

References Cited by the Examiner UNITED STATES PATENTS WILLIAM F ODEA,Primary Examiner.

ISADOR WEIL, Examiner.

D. LAM ERT, ss stant Examine

1. IN A MIXING VALVE HAVING A PAIR OF INDIVIDUALLY ENERGIZABLE SOLENOIDCOILS ARRANGED IN SIDE-BY-SIDE RELATION FOR CONTROLLING THE FLOW OFFLUIDS THROUGH THE VALVE; THE IMPROVEMENT COMPRISING A SPOOL FOR EACHCOIL; A FIRST TERMINAL MOUNTED ONE ONE SPOOL IN ELECTRICAL CONNECTIONWITH ONE END OF THE COIL CARRIED THEREON; A SECOND TERMINAL MOUNTED ONTHE OTHER SPOOL IN ELECTRICAL CONNECTION WITH ONE END OF THE COILCARRIED THEREON; A THIRD TERMINAL MOUNTED JOINTLY ON BOTH SPOOLS ISELECTRICAL